Phosphorus-containing products

ABSTRACT

PHOSPHORUS-CONTAINING PRODUCTS ARE PREPARED BY TRANSESTERIFYING NEUTRAL PHOSPHATE POLYOLS WITH ETHYLENE OXIDE ADDUCTS OF POLYPROPYLENE GLYCOL. THE RESULTING PRODUCTS EXHIBIT SURFACE ACTIVE PROPERTIES.

United States Patent 70 9, 1966, now Patent No. 3,530,205. This application May 10, 1971, Ser. No. 141,961

Int. Cl. C07f 9/02 us. 01. 260-920 V 6 Claims ABSTRACT OF THE DISCLOSURE Phosphorus-containing products are prepared by transesterifying neutral phosphate polyols with ethylene oxide adducts of polypropylene glycol. The resulting products exhibit surface active properties.

The present application is a continuation-in-part of copending US. Patent Application Ser. No. 879,506, filed Nov. 24, 1969, now abandoned which, in turn, is a continuation-in-part of US. Patent Application Ser. No. 556,266, filed June 9, 1966 now US. Pat. No. 3,530,205.

Phosphate polyols prepared by the reaction of alkylene oxides with phosphoric acid are well known in the art. These polyols, as a result of their reactive hydrogen atoms, have found utility in a number of applications including flame-retardant polymers, particularly rigid polyurethane foams. To improve the properties of these polyols, various modifications have been proposed. In one modification, an alkylene oxide is initially reacted with a long-chain organic compound having an active'hydrogen atom and the resulting compound is further reacted with an acid of phosphorus to obtain a phosphorus-containing compound having long chains. The reactions mentioned above are very complex and must be carefully controlled. Furthermore, because of the difficulties associated with these reactions, only a select number of reactants may be successfully employed if the above course of reaction is followed.

In accordance with the present invention, it has been determined that new phosphorus-containing products may be prepared by transesterifying, with an organic compound containing at least two hydroxyl groups, an essentially neutral phosphate polyol prepared by the reaction of a phosphoric acid having a P 0 equivalency of from about 72% to about 95% with an alkylene oxide. It is surprising and unexpected that the transesterification so readily occurs in accordance with this invention since heretofore the transesterification of phosphate polyols was considered to proceed so slowly that a number of organic chemists have said that the reaction does not occur. John R. Van Wazer, Phosphorus And Its Compounds, Vol. 1, page 585. The new polymers of this invention range from pourable liquids to high-viscosity rubber-like products, thus affording application in polyurethane foams and in polyester resins, as plasticizer in vinyl resins, as additives for functional fluids, and as surface active agents. To illustrate, the products prepared by transesterifying a neutral phosphate polyol with polyhydric alcohols or alkylene oxide 3,822,326 Patented July 2, 1974 ice,

adducts thereof, as a result of their increased hydroxyl content, demonstrate excellent utility in the preparation of flame-retardant, rigid polyurethane foams. Products prepared from aromatic-containing transesterifying agents demonstrate marked improvements in the structural properties of polyurethane foams prepared therefrom. Products prepared from those alkylene oxide adducts which are surface active demonstrate excellent utility in a number of detergent applications.

The essentially neutral phosphate polyols which are transesterified into the phosphorus-containing products of the present invention may be prepared in several ways. Preferably, however, they are prepared by the direct reaction of an alkylene oxide with a phosphoric acid. They may also be prepared by oxidation of the corresponding phosphite polyol by the method disclosed in US. Pat. No. 3,081,331.

The exact structure obtained when the essentially neu tral reaction products are transetsterified in accordance with the present invention is unknown. Unquestionably, a mixture of compounds having difierent chemical structures is obtained. Some of the compounds contain recurring oxyphosphorus units while others contain longchain oxyalkylene units, while still others contain a combination of phosphorus and similar and/ or dissimilar unsymmetrical and/or symmetrical oxyalkylene units. In view of this uncertainty, applicants do not wish to be bound by any exact chemical structure and will refer to their new polymers as the products from the transesterification of essentially neutral reaction products of alkylene oxides and acids of phosphorus.

The amounts of alkylene oxide and acid of phosphorus which are necessary to prepare the essentially neutral phosphate polyols which are transesterified into the new polymers of this invention will vary, depending upon the alkylene oxide used and the P 0 equivalency of the acid selected. For example, if propylene oxide and 100% phosphoric acid are the selected reactants, about six moles of propylene oxide per mole of acid is required to prepare the essentially neutral phosphate polyols. With higher molecular weight alkylene oxides and 100% phosphoric acid, less than six moles of the oxide per mole of the acid will give the desired phosphate polyols.

Acids of phosphorus which may be used in the preparation of the phosphate polyols which are transesterified according to this invention are those acids corresponding to 21 P 0 equivalency of from about 72% to about Representative acids include the to 131% phosphoric acids such as orthophosphoric acid, pyrophosphoric acid, polyphosphoric acid and certain metaphosphoric acids.

Alkylene oxides which may be used in the preparation of the phosphate polyols which are transesterified according to this invention include ethylene oxide, propylene oxide, the isomeric normal butylene oxides, hexylene oxide, octylene oxide, dodecene oxide, methoxy and other alkoxy propylene oxides, styrene oxide and cyclohexene oxide. Halogenated alkylene oxides may also be used, such as epichlorohydrin, epiiodohydrin, epibromohydrin, 3,3-dichloropropylene oxide, 3 chloro-1,2-epoxypropane, 3- chloro-1,2-epoxybutane, 1-chloro-2,3-epoxybutane, 3,4-di chloro-1,2-epoxybutane, 1,4-dichloro-2,3-epoxybutane, 1-

3 chloro 2,3 epoxybutane, and 3,3,3-trichloropropylene oxide. Mixtures of any of the above alkylene oxides may also be employed.

The organic compounds which are employed in accordance with the present invention are those compounds containing at least two hydroxy groups. Representative compounds include polyhydric alcohols, polysaccharides and derivatives thereof, and alkylene oxide adducts of compounds containing at least two active hydrogen atoms. Mixtures of any of the above may also be used. Polyhydric alcohols and the alkylene oxide adducts mentioned above are the preferred compounds.

Polyhydric alcohols which may be employed in accordance with the present invention include ethylene glycol, propylene glycol, glycerine, trimethylolpropane, hexanetriol, pentaerythritol, sucrose, sorbitol, mannitol and bisphenol A. Also included in the term polyhydric alcohols as employed in the present invention are those triglycerides such as castor oil which, because of their reactive hydroxyl groups, behave as to the standard polyhydric alcohols.

Polysaccharides and derivatives thereof which may be employed in accordance with the present invention include alpha-methylg-lucoside, maltose, cellulose, cellulose ethers starch, starch ethers, amylose, amylopectin and dextrose.

Alkylene oxide adducts of compounds containing at least two active hydrogen atoms which may be employed in accordance with the present invention include the alkylene oxide adducts of any of the polyhydric alcohols and polysaccharides mentioned above, as well as adducts of any other compound having at least two active hydrogen atoms as determined by the Zerewitinoff test described by Kohler in J. Am. Chem. Soc., 49 3182 (1927). The active hydrogen atoms are usually attached to oxygen, nitrogen, or sulfur atoms. Thus, suitable active hydrogen-containing groups include OH, NH, COOH and SH. Compounds which contain two or more different groups within the above-defined classes may also be used such as amino alcohols.

In addition to the polyhydric alcohols, oils and polysaccharides mentioned above, other compounds having at least two active hydrogen atoms which may be adducted with alkylene oxide include mercaptans such as 1,2-ethane dithiol, 1,2-propane dithiol, 1,6-hexane dithiol, and 1,2,3-propane trithiol; acids such as oxalic acid, succinic acid, adipic acid, suberic acid, maleic acid, fumaric acid, isophthalic acid, terephthalic acid, aconitic acid, and trimellitic acid; hydroxyl-containing polyesters such as those prepared from any of the above acids and dihydric alcohols such as ethylene glycol and propylene glycol; amines such as aniline, orthoand para-phenylene diamine, the isomeric tolylene diamines, diethanolamine, ethylamine, ethylene diamine, propylene diamine, diethylene triamine, and triisopropanolamine; amides such as n-octyl amide, n-dodecyl amide; n-oleic amide, and :,wdodecandioic amide; sulfonamides such as benzene disulfonamide and n-octylsulfonamide; and thioamides such as benzene disulfonthioamide. Alkylene oxides which may be employed in the preparation of these adducts include those mentioned above in the preparation of the essentially neutral phosphate polyols. Preferred alkylene oxide adducts which are employed in accordance with the present invention include the'propylene oxide adducts of polyhydric alcohols or polyalkylene polyamines as well as the adducts prepared from the reaction of mixtures of propylene oxide and ethylene oxide with polyhydric alcohols or polyalkylene polyamines. Adducts prepared from mixtures of alkylene oxides may either have a block or heteric structure. Both of these types of adducts are operable in the present invention.

Particularly preferred organic compounds which may be employed in accordance with the present invention are ethylene oxide adducts of polypropylene glycol. These adducts may be represented by the formula wherein a is an integer such that the hydrophobe represented by (C H O) has a molecular weight of from 950 to 4000, preferably from 1200 to 1750, and b is an interger such that the hydrophile represented by (C H O) constitutes from about 10 to 90, preferably from 40 to 80, weight percent of the adduct. The amount of adduct employed in the transesterification reaction of the present invention may vary from 0.25 mole to 3.0 moles, preferably from 0.50 mole to 1.5 moles of adduct per mole of neutral phosphate polyol.

The hydrophobe of the above adducts is prepared by adding propylene oxide to the two hydroxyl groups of a propylene glycol nucleus. By adding ethylene oxide to the hydrophobe, it is possible to place polyoxyethylene hydrophilic groups on both ends of the molecule. These hydrophilic polyoxyethylene groups may be controlled to constitute anywhere from 10% to of the final molecule. A more detailed explanation of the preparation of these adducts may be found in US. Pat. No. 2,674,619.

The products of the present invention are prepared by adding an essentially neutral reaction product of a phosphoric acid and an alkylene oxide to an organic compound having at least two active hydroxyl groups and heating the reaction mixture at temperatures of from about 50 C. to 200 C., preferably 80 C. to 150 C., at reduced pressures. Pressures of from less than one millimeter of mercury up to millimeters of mercury are preferred. If desired, a catalyst may be employed. Typical catalysts include metallic sodium, organic amines and inorganic bases. The time required for the transesterification reaction may vary from about two to about 100 hours, depending upon the particular reactants, the catalyst employed, if any, and the temperature and pressure of the reaction. An inert diluent may also be employed if desired. In those instances where a polysaccharide is employed as the transesterifying agent, it is often advantageous to employ such a diluent. Typical diluents include aromatic hydrocarbons such as benzene and toluene, chlorinated hydrocarbons such as carbon tetrachloride, perchloroethylene and chlorobenzenes, and ketones such as acetone and methylethylketone.

The following examples serve to illustrate the invention. All parts are by weight unless otherwise specified.

EXAMPLES I-XV In the following examples, various organic compounds having at least two hydroxyl groups were employed in the transesterification of an essentially neutral reaction products of six moles of propylene oxide and one mole of orthophosphoric acid (P 0 equivalency of 72% This transesterification occurred in the following manner.

The organic compound was charged to a reaction vessel equipped with a nitrogen source, thermometer, stirrer and heat exchange means. The compound was heated at 100 C., at about one to five millimeters of mercury, under nitrogen for about two hours. After cooling to room temperature, the orthophosphoric acid-propylene oxide reaction product described above was added to the vessel and the reaction mixture was heated at from about 80 C. to C. for from four to twelve hours at from one to ten millimeters of mercury. During the course of the reaction, a homogeneous phase developed and volatile liquids were distilled from the reaction mixture. The reaction product was then removed from the vessel and analyzed. The specific reactants and amounts thereof, as Well as product characterizations, are presented in Table l.

TABLE 1 Reactants Propylene oxidephosphoric acid adduct (parts) Organic compound Part Example:

I Glyeerlne...

l 22. 3 N,N N',N'tetrakls- (2-hydroxypropyl)- ethylene diamlne. 212 gisphenol A Product Hydroxyl number characterizations Percent phosphorus H=850 molecular weight adduct of propylene oxide and sucrose.

EXAMPLE XVI Various rigid polyurethane foams were prepared by mixing, in each instance, about 23 parts of the product of Examples I, II, III, V and X-XV along with:

17.4 parts of tolylene diisocyante,

0.2 parts of a silicone surfactant,

5.0 parts of a halogenated hydrocarbon blowing agent, 0.8 part of trimethylpiperazine, and

0.6 part of stannous octoate.

The resulting foams did not shrink, were resistant to humidity, and possessed excellent flame-retardant properties.

EXAMPLE XVII The reaction products of Examples VI-IX were evaluated as surface active agents in accordance with the Carbon Soil Removal Test as described in US. Pat. No. 2,677,700, columns 1416, and Tagged Clay Soil Removal Test as described in Journal American Oil Chemists Society, 42, pp. 993-97 (1965). The results of this evaluation appear in Table 2.

TAB LE 2 Carbon soil Tagged clay removal soil Product of example CSR WR S R WR EXAMPLE XVIII Following the procedure of Example I, 120 parts of an essentially neutral reaction product of 115% phosphoric acid (P equivalency of 82.3%) and propylene oxide was transesterified with 86 parts of a polyol prepared from two moles of propylene oxide and one mole of bisphenol A and 257 parts of a polyol prepared from one mole of sucrose and two moles of propylene oxide. An amber-colored liquid product (431.6 parts) was obtained having a refractive index of n 1.4924 a hydroxyl number of 370, an acid number of 1.97 and 6.3% phosphorus. A polyurethane foam prepared from this product exhibited excellent structural and flame-retardant properties.

EXAMPLE XIX Following the procedure of Example I, 120 parts of an essentially neutral reaction product of 115 phosphoric acid and propylene oxide was transesterified with 86 parts of a polyol prepared from two moles of propylene oxide and one mole of bisphenol A, and 257 parts of a polyol prepared from one mole of pentaerythritol and two moles of propylene oxide. A yellow liquid product (409.6 parts) was obtained having a refractive index of n 1.4860, a hydroxyl number of 410, an acid number of 3.66 and 6.4% phosphorus.

EXAMPLE XX Following the procedure of Example I, 120 parts of an essentially neutral reaction product of 115% phosphoric acid and propylene oxide was transesterified with 86 parts of a polyol prepared from two moles of propylene oxide and one mole of bisphenol A and 257 parts of a polyol prepared from a-methyl glucoside and and propylene oxide. An amber liquid product (409.6 parts) was obtained having a refractive index of n 1.4886, a hydroxyl number of 339, an acid number of 0.35 and 6.4% phosphorus.

We claim:

1. A phosphorus-containing product prepared by transesterifying, at temperatures between 50 C. and 200 C. under reduced pressure of from less than 1 millimeter of mercury to 100 millimeters of mercury,

(a) an essentially neutral phosphate polyol prepared by the reaction of an oxide selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide, hexlyene oxide, octylene oxide, dodccene oxide, methoxy propylene oxide, styrene oxide, cyclohexene oxide, epichlorohydrin, epiiodohydrin, epibromohydrin, 3,3 dichloro-propylene oxide, 3 chloro 1,2-epoxybutane, 1-chloro-2,3-epoxybutane, 3,4-dichloro 1,2-epoxybutane, 1,4-dichloro- 2,3-epoxybutane, l chloro 2,3 epoxybutane, 3,3,3 trichloropropylene oxide, and mixtures thereof with a phosphoric acid having a P 0 equivalency of from 72% to 95% with (b) a compound having the following formula wherein a is an integer such that the hydrophobe represented by (C H 0) has a molecular weight of from 950 to 4000, and b is an integer such that the hydrophile represented by (C H 0) constitutes from about 10 to weight percent of the compound employing a mole ratio of (b) to (a) of from 0.25:1 to

2. The product of claim 1 wherein the oxide is propylene oxide.

3. The product of claim 1 wherein the phosphoric acid is 100% phosphoric acid.

4. The product of claim 1 wherein a is an integer such that the hydrophobe represented by (C H O) has a molecular weight of from 1200 to 1750, and b is an integer such that the hydrophile represented by (C H O) constitutes from about 40 to 80 weight percent of the compound.

5. The product of claim 1 where a is an integer such that the hydrophobe represented by (C H O) has a molecular weight of 1750, and b is an integer such that the hydrophile represented by (C H O) constitutes about 80 weight percent of the compound.

6. The product of claim 1 wherein the alkylene oxide is propylene oxide, the phosphoric acid is 100% phosphoric acid, and a is an integer such that the hydrophobe represented by (C H O) has a molecular weight of from 1200 to 1750 and b is an integer such that the hydrophile represented by (C H O) constitutes from about 40 to 80 weight percent of the compound.

References Cited UNITED STATES PATENTS 

